A three-dimensional structure is often represented as a point cloud having a three-dimensional coordinate. However, direct use of many pieces of point cloud data is inefficient.
Therefore, there has been proposed a method in which the point cloud data is divided in a certain unit and is structured to reduce a data amount. For example, PTL 1 discloses a technique of representing a region where a forward object exists in a range image obtained by a stereo camera as a group of strip-shaped segments (hereinafter, referred to as “Stixel”).